1. Field of the Invention
Among other things, the present invention is related to induction drives for either straight or curved conveyors as well as methods of driving endless conveyor belts. Generally, pivotable magnets are interconnected serially and dimensioned to traverse a groove of the conveyor bed which can be either straight or curved. The series of pivotable magnets renders a virtual continuous magnetic body, and upon encountering the stator""s electromagnetic field, a magnetic flux for driving the virtual continuous magnetic body is created. Select embodiments of the present invention incorporate free floating pivotable magnets housed in a holder attached to the nonmagnetic endless conveyor belt and dimensioned to ride the groove of the conveyor bed. Either the holder or the magnets can be dimensioned to ride in a track of the side wall of the conveyor bed""s groove. And still in accordance with the present invention, the conveyor""s direction can easily be reversed by altering the direction of the electric current flowing through the stator or stators while, at the same time, the pivotable magnets are dimensioned so they will not interlock with each other, as the conveyor""s direction is reversed. In other words, the pivotable magnets are sized to move through the groove""s curves, as well as about rollers that alters the course or direction of the conveyor belt.
2. Description of the Previous Art
a) U.S. Pat. No. 5,172,803xe2x80x94Lewin, discloses a conveyor belt having a magnetic motor linear drive. Endless belt (2) is spanned over downstream and upstream rollers (33) and (34). Belt (2) has an inner surface (10) provided at each of the reinforced zones (6), (7) and (8) with ridge (9) in which is imbedded permanent magnet (5). Under each magnet (5) is a respective stator (4) that can be energized by alternating current. Along with teaching rectangular, flat, cylindrical, ridged, particulate, meshed, powdered permanent magnets embedded into belt (2), the ""803 Patent also describes embedding magnets (5) into ridge (58). According to Lewin, his permanent magnets are fixed to the linear surface of the belt in combination with a juxtaposed stator form a linear motor for advancing his upper stretch downstream.
b) U.S. Pat. No. 2,655,195xe2x80x94Curtis enables a rubberized magnetic conveyor belt. The ""195 Patent""s flexible resilient rubber-like layers 12 including the Curtis magnetic composition are impregnated into and disposed over layers 11 by frictioning or coating and serve to bond layers 11 into the belt carcass.
c) U.S. Pat. No. 2,684,753xe2x80x94Kolbe, et. al., enables a magnetic drive for conveyor belts. Each of the drive units (16) includes traction belt (20) that is guided over end rollers (22). One of the rollers (22) receives pulley belt (24) which is directed by pulley (26) that is driven by conventional electric motor (24) connected to standard gear reducer (30). Disposed below each roller (34) is the electromagnetic roll (38) wound about an armature curved to conform with roller (34).
d) U.S. Pat. No. 2,873,843xe2x80x94Wilson discloses a conveyor for moving ferromagnetic license plates. Magnets (32) are secured to the outer surface of inner belt (15) while outer belt (12) is provided with apertures (24). Drive motor (40) turns drive shaft (42) of pulley (26) which rotates inner conveyor (14). When Wilson""s magnets (32) contact the surface of the license plates, the license plates are held on the conveyor via magnetic attraction.
e) U.S. Pat. No. 3,169,632xe2x80x94Kain enables a magnetic flexible cable that has been incorporated into the conveyor belt. The Kain magnet is mounted in a trough underneath the conveyor belt.
f) U.S. Pat. No. 3,620,357xe2x80x94Folkes teaches primarily a belt conveyor for passengers. The ""357 Patent""s belt is supported by magnetic repulsion. Magnetization is such that polarity of outer surface of layer (15) and the outer surface of layer (17) are the same. Thus, in use there is a distributed upward thrust on the belt. Primarily, Folkes utilizes barium ferrite for his magnetizable material distributed in his belt, but strontium as well as lead ferrite also are functional.
g) U.S. Pat. No. 4,643,298xe2x80x94Wallaart enables a magnetic bend for a chain conveyor. Wallaart""s base includes two upright legs (2 and 3) that form the rails for the conveyor chain. Permanent magnets (7) are inserted into pockets (13) are formed on the underneath side of legs (2and3). Compressible plastic or rubber (8) between the closure strip (10) and magnet (7) ensure the magnets in pockets (13) are pushed upwards in the bend segment to enable the magnets to exert maximum force of attraction on the chain links (4).
h) U.S. Pat. No. 5,890,583xe2x80x94Garbagnati discloses a magnetic curve for a chain conveyor. Curve (10) includes base (11) and slide portion (12) to which chain conveyor (13) is fastened. Operation of the curve is accomplished by attaching ferromagnets (17) to guide (12) with screws (18).
i) U.S. Pat. No. 5,295,568xe2x80x94Saito, et. al., enables a passenger conveyor. Generally, the conveyor""s treadboards move horizontally, but the conveyor can also be utilized as an inclined escalator. Regardless of which Saito embodiment is selected, the flattened linear motor""s stators and moving members are positioned horizontally between the advance and return travel paths of the treadboards. Additionally, the ""568 Patent teaches that moving member (12) is composed of a nonmagnetic conductor such as aluminum and copper, or a nonmagnetic conductor laminated on the surface of the magnetic material. Moving members (12) are fixed securely to reinforcement member (7B) mounted on the reverse side of treadboard (5). Stators (13) are supported by horizontal members (3) of frame (1) so as to be opposed to moving members (12a and 12b). Energizing stators (13) apply driving force to moving members (12) to move treadboards (5) along advance (4U) and return (4D) guide rails.
j) U.S. Pat. No. 3,788,447xe2x80x94Stephanoff describes a linear motor conveyor. Stephanoff""s guide track (20) includes two halves that are spaced apart to define a slot (40) therebetween. Except for the curve from upper transport run (12a) to lower return run (12b), support surfaces (30 and 32) of guide (20) are horizontal. Vertical stem (18) of conveyor segment (16) is conducting non magnetic copper or aluminum so that a propulsive force will be generated on stem (18) by the traveling field in stators (62). Stators (62) are located on both sides of slot (40) or a laminated core (74) is mounted in guide (20) to provide the return path for electromagnetic flux. Propulsive force in registration with the linear motor stators causes the entire conveyor to circulate around the guide.
k) U.S. Pat. No. 5,027,942xe2x80x94Wallaart teaches a hinged chain conveyor. Rails 3 and 4 have permanent magnets 9 and 10 inserted into at least the bend sections of the rails.
l) U.S. Pat. No. 5,165,527xe2x80x94Garbagnati enables a chain conveyor that includes a magnetizable chain. Magnets (19) are inserted into grooves (15 and 16) of shoulders (11 and 12) of guide track (10) to assist in controlling ferromagnetic chain (14) as the chain moves through bends of the conveyor.
m) U.S. Pat. No. 5,199,551xe2x80x94Wallaart, et. al., discloses a bend segment for a chain conveyor. Permanent magnets (8) are arranged in chambers of plastic bend segment.
n) U.S. Pat. No. 5,298,804xe2x80x94Ecker, et. al., enables a curved conveyor belt with supporting frame devoid of belt band rollers. On the opposite side of stator (12), guide ducts (10 and 11) include recess (14) through which running wheel carrier (15) grasps carrying bar (16) and wheels (25 and 26). Wheel carrier (15) is connected to side edges (18 and 19) of belt band (2). Drive is applied via linear motor system (4) that includes stator (12) and magnet (23) that is integrated with crossbar (22) of carrying spar (16).
o) U.S. Pat. No. 3,426,887xe2x80x94Ward, et. al., among other things, discloses the use of introducing a metal strip or applying metallic particulars to the lateral edges of a nonmetallic conveyor belt. The combination of the coil and the ferrous metallic edge forms a type of the Ward linear induction motor. The ""887 Patent""s disclosure is limited to mechanisms that convey in the horizontal plane.
p) U.S. Pat. No. 4,981,208xe2x80x94Jones enables a magnetic spiral conveyor system. Among other things, Jones teaches embedding permanent magnets (32) into the exposed edge of module (28) which contacts the driving bars (26) of the system. In this manner, frictional contact between the conveyor belt and the driving bars is increased.
Unlike traditional induction driven conveyors, the present invention does not require use of chains or bead guidance devices to control and/or measure the pathway and/or distance traveled by the endless conveyor belts associated with curved conveyors. At the same time and still in accordance with the current invention, the virtual magnetic body can pull, i.e., drive, either straight or curved conveyors. Pivotable magnets incorporated into the virtual magnetic body can be connected to the endless conveyor belt in any manner acceptable in the art, including but not limited to nuts and bolts, rivets, thread or adhesives. Additionally, the magnets can be dimensioned to ride in tracks of the side walls of the conveyor bed""s groove, or they can float freely in a holder that is attached to conveyor belt. In one embodiment, the pivotable magnets are hinged with each previous and each subsequent pivotable magnet to interconnect serially the members of the virtual continuous magnetic body. A protective coating can be applied to the pivotable magnets to enhance their effective working life.
An object of the present invention is to provide a bi-directional traveling magnet.
Still another object of the present invention is to provide an induction drive for a conveyor.
It is another object of the present invention to enable a method of using an induction driven conveyor.
Yet another object of the present invention is to provide a drive for an endless belt incorporating a plurality of serially interconnected pivotable magnets, wherein each pivotable magnet is also attached individually to the endless belt.
Still another object of the present invention is to provide a drive including a hinged pivotable magnet.
Yet still another object of the present invention is provide an induction driven conveyor that does not require use of chain guidance.
It is yet another object of the present invention to provide an induction driven conveyor that does not require use of bead guidance.
Still another object of the present invention is to provide a bi-directional induction driven conveyor where the direction of conveyor is reversible by altering the direction of the electric current flowing through the stator.
Yet still another object of the present invention is provide an induction driven conveyor utilizing at least two stators for generating a cumulative electromagnetic field.
It is yet still another object of the present invention to provide a pivotable magnet dimensioned for riding in the track of a side wall of the bed""s groove.
Still another object of the present invention is to provide a virtual continuous magnetic body having a plurality of free floating pivotable magnets contained within a holder that is dimensioned for riding in the groove of the conveyor bed.
Yet still another object of the present invention is to provide a virtual continuous magnetic body having a protective coating for enhancing the life of the pivotable magnets.
It is yet another object of the present invention to provide an induction drive that can be utilized in either a straight or a curved conveyor.
Still another object of the present invention is to provide an induction drive that can generate from about 248 Watts to about 7.5 Kilowatts.
An embodiment of the present invention can be described as a flux dependent plurality of bi-directional traveling magnets, comprising: a bed in which the traveling magnets move, wherein the bed further includes: a groove running a length of said bed including a first side having a first track for interlocking the traveling magnets, a second side having a second track for interlocking the traveling magnets opposite of and substantially parallel to the first side; a stator including a face projecting an electromagnetic field toward the plurality of traveling magnets; a switch for controlling direction of electric current flowing through the stator such that the plurality of traveling magnets move through the groove in response to a current dependent flux generated between the first stator and the plurality of traveling magnets; a virtual continuous magnetic body rendered by a cooperation of adjacent and overlapping members of the plurality of traveling magnets and the electromagnetic field; and wherein each of the plurality of traveling magnets further comprises: a dimension for interlocking the first track and the second track of said groove, and a hinge for interconnecting serially an adjacent member of said plurality of traveling magnets.
Another embodiment of the present apparatus can be described as an electromagnetic induction driven bi-directional conveyor, comprising: a frame; a guide supported by the frame, wherein said guide further comprises: a bed having a groove running a length of the including a first side, and a second side opposite of and substantially parallel to the first side; a first roller, having a notch, located near a first distal edge of the bed; a second roller, having a notch, located near a second distal edge of the bed opposite the first distal edge of the bed; an endless nonmagnetic belt directed by the guide, wherein the endless nonmagnetic belt further comprises: a roller engaging side, and a non-roller engaging side opposite the roller engaging side; a first stator including a face projecting a first electromagnetic field toward the roller engaging side of the endless nonmagnetic belt; and a plurality of pivotable magnets serially interconnected to each other and individually attached to the nonmagnetic belt such that the pivotable magnets traverse, in series, the groove in response to a magnetic flux created between the first stator""s face and the pivotable magnets encountering the first electromagnetic field.
Yet another embodiment of the present device can be described as an electromagnetic induction driven bi-directional conveyor, comprising: a frame; a guide supported by the frame, wherein the guide further comprises: a bed having a groove running a length of the bed including a first side having a first track and a second side opposite of and substantially parallel to the first side, a first roller, having a notch, located near a first distal edge of the bed and a second roller, having a notch, located near a second distal edge of the bed opposite the first distal edge of the bed; an endless nonmagnetic belt directed by the guide, wherein the endless nonmagnetic belt further comprises: a roller engaging side and a non-roller engaging side opposite the roller engaging side; a first stator, including a first face projecting a first electromagnetic field toward the roller engaging side of the endless nonmagnetic belt, mounted to the frame; a second stator, including a second face projecting a second electromagnetic field toward the non-roller engaging side of the endless nonmagnetic belt, mounted to the frame; a plurality of overlapping pivotable serially hinged magnets attached to the nonmagnetic belt such that the overlapping pivotable serially hinged magnets ride in the track of the groove; and render a virtual continuous magnetic body for driving the bi-directional conveyor, traverse, in series, the groove in response to a cumulative magnetic flux created between the first and the second electromagnetic fields and the virtual continuous magnetic body encountering the first and the second electromagnetic fields and rotate, in series, about the first and the second roller; and a protectant for the virtual continuous magnetic body.
In still another embodiment, the present invention can be described as an electromagnetic induction driven bi-directional conveyor, comprising: a frame; a guide supported by the frame, wherein the guide further comprises: a bed having a groove running a length of the bed; and wherein the groove further includes: a first side and a second side opposite of and substantially parallel to the first side; a first roller, having a notch, located near a first distal edge of the bed; a second roller, having a notch, located near a second distal edge of the bed opposite the first distal edge of the bed; an endless nonmagnetic belt directed by the guide, wherein the endless nonmagnetic belt further comprises: a roller engaging side and a non-roller engaging side opposite the roller engaging side; a first stator including a face projecting a first electromagnetic field toward the roller engaging side of the endless nonmagnetic belt; and a holder attached to the endless nonmagnetic belt and containing a plurality of pivotable magnets such that the holder traverses the groove in response to a magnetic flux created between the first stator""s face and the pivotable magnets encountering the first electromagnetic field.
Yet another embodiment of the present device can be described as an electromagnetic induction driven bi-directional conveyor, comprising: a frame; a guide supported by the frame, wherein the guide further comprises: a bed having a groove running a length of the bed including a first side having a first track and a second side opposite of and substantially parallel to the first side, a first roller, having a notch, located near a first distal edge of the bed and a second roller, having a notch, located near a second distal edge of the bed opposite the first distal edge of the bed; an endless nonmagnetic belt directed by said guide, wherein the endless nonmagnetic belt further comprises: a roller engaging side and a non-roller engaging side opposite the roller engaging side; a first stator, including a first face projecting a first electromagnetic field toward the roller engaging side of the endless nonmagnetic belt, mounted to the frame; a second stator, including a second face projecting a second electromagnetic field toward the non-roller engaging side of the endless nonmagnetic belt, mounted to the frame; and a bendable holder attached to the endless nonmagnetic belt for traversing the groove: wherein the bendable holder further contains a plurality of pivotable magnets such that the bendable holder traverses the groove in response to a cumulative magnetic flux created between the first stator""s face, the second stator""s face and the pivotable magnets encountering the first electromagnetic field and the second electromagnetic field, and wherein the holder is dimensioned to ride in a track in a side of the groove, and wherein each of the plurality of pivotable magnets is hinged serially to each previous and each subsequent pivotable magnet.
Still another embodiment of the present invention can be described as a method of driving a nonmagnetic endless conveyor belt, comprising the steps of: mounting a bed, including a groove, to a frame for supporting the nonmagnetic endless conveyor belt; locating a notched roller at each end of the bed for altering direction of the nonmagnetic endless conveyor belt; attaching a plurality of pivotable magnets to the nonmagnetic endless conveyor belt; dimensioning each of the plurality of pivotable magnets to ride in the groove; serially interconnecting each of the plurality of pivotable magnets such that a virtual continuous magnetic body is created; positioning a first stator to face a roller engaging side of the nonmagnetic endless conveyor belt; energizing the first stator to generate a magnetic flux between the first stator and the virtual continuous magnetic body encountering the first stator""s electromagnetic field; using the magnetic flux created between the first stator""s electromagnetic field and the virtual continuous magnetic body to push the continuous magnetic body; guiding the virtual continuous magnetic body through the groove and about the notches; and pulling the nonmetallic endless conveyor belt with the virtual continuous magnetic body.
Yet another embodiment of the present invention can be described as a method of driving a nonmagnetic endless conveyor belt, comprising the steps of: mounting a bed, including a groove, to a frame for supporting the nonmagnetic endless conveyor belt; locating a notched roller at each end of the bed for altering direction of the nonmagnetic endless conveyor belt; containing a plurality of free floating pivotable magnets inside a bendable holder such that a virtual continuous magnetic body is created; dimensioning the bendable holder to ride in the groove; positioning a first stator to face a roller engaging side of the nonmagnetic endless conveyor belt; energizing the first stator to generate a magnetic flux between the first stator and the virtual continuous magnetic body encountering the first stator""s electromagnetic field; using the magnetic flux created between the first stator""s electromagnetic field and the virtual continuous magnetic body to push the continuous magnetic body; guiding the virtual continuous magnetic body through the groove and about the notches; and pulling the nonmetallic endless conveyor belt with the virtual continuous magnetic body.
It is the novel and unique interaction of these simple elements which creates the apparatus and methods, within the ambit of the present invention. Pursuant to Title 35 of the United States Code, descriptions of preferred embodiments follow. However, it is to be understood that the best mode descriptions do not limit the scope of the present invention.